Pulsed electromagnetic energy has long been used to promote healing in humans. The DIAPULSE™ machine was developed as an improvement on the previous methods of diathermy which used electromagnetic energy to radiate heat deep into the human tissue. The goal of the DIAPULSE machine was to increase the strength of the electromagnetic field without generating increased heat in the tissue. This was accomplished by pulsing the electromagnetic field in very short pulses, referred to as “ultra-short wave therapy”. High frequency electromagnetic waves could be applied with increased voltage without overly heating the patient's tissue by applying the waves in pulses of very short duration. This “athermapeutic” method was found to provide therapeutic benefits without generating significant heat in the living matter.
For example, U.S. Pat. No. 2,276,995 issued Mar. 17, 1942 discloses a pulse generating circuit for applying electromagnetic radiation to a patient wherein the frequency of the electromagnetic waves is about 25 megacycles per second, and the energy is applied in pulses having a duration of about 1/20000 of a second and a frequency of about 900 per second, so that the interval between pulses is at least 10 times the pulse duration.
One of the limitations of the Diapulse machine's athermapeutic method was the fact that government regulations severely limited the frequency at which such machines could operate so as to avoid interfering with radio and television broadcasts. Consequently the Diapulse machine was designed to operate at a fixed ham radio frequency of 27.12 megacycles. See U.S. Pat. No. 3,043,310 issued Jul. 10, 1962 and U.S. Pat. No. 3,181,535 issued May 4, 1965. A solid state version of the Diapulse machine is disclosed in U.S. Pat. No. 3,670,737 issued Jun. 20, 1972. The machine has been applied to the treatment of migraine headaches (U.S. Pat. No. 5,718,721 issued Feb. 17, 1998), and wound healing. The machines are typically operated at a pulse duration of 65 microseconds and frequency of 600 pulses per second.
It has been found that frequencies other than 27.12 megacycles are more effective for electrotherapy of living matter using pulsed electromagnetic frequencies, but that such frequencies vary according to the application and living matter. There remains a need for useful electrotherapy of living matter using pulsed electromagnetic frequencies at an optimally effective frequency.